Researchers explore ocular lesions in monkeypox virus infections

By Pooja Toshniwal PahariaAug 24 2022Reviewed by Aimee Molineux

In a recent case report published in the Journal of Infection, researchers highlighted the virological and clinical characteristics of monkeypox virus (MPXV) infections with ocular involvement.

In the current 2022 MPXV outbreak, MPX cases have been reported predominantly among men who have sex with men (MSM) with no epidemiological association with endemic nations. MPX is usually a mildly intense and self-limiting illness with rare complications and does not require targeted antiviral agents to improve disease outcomes.

Antiviral therapeutic agents have been administered in cases with heightened severity or complications and lesions at sites with increased risk of MPX sequelae. In particular, ocular complications have rarely been reported in the current outbreak cases compared to those identified in endemic nations.

About the case report

In the present case report, researchers described a case of MPX with ocular complications identified in May 2022 in an MSM patient in Italy.

A male aged 26 years presented at an outpatient department with papules (n=2) in the region situated above the pubic area and was diagnosed with MPX using real-time polymerase chain reaction (PCR) from dermatological lesion specimens. He had a history of protected sex five days before the outpatient visit with a man diagnosed as MPXV-positive by real-time PCR based on MPXV-deoxyribonucleic acid (DNA) in conjunctival and eyelid swabs and by MPXV isolation in cell cultures.

After two days of the initial visit, the patient was hospitalized with malaise, fever, headaches, enlarged inguinal lymph nodes, and several papules in the eyelid of the right side with progressive conjunctival and periorbital involvement. Based on the clinical presentation, a bacterial superinfection was suspected, and therefore, topical steroids were administered with intravenous (I.V.) antibiotics.

Over time, lesion counts in the ocular fornix, and lower and upper eyelids were elevated, and the patient additionally presented with hyperemia in the conjunctival region and edema in the periorbital region. Subsequently, swabs from the conjunctival and periorbital lesion areas were obtained and analyzed for the presence of MPXV DNA by real-time PCR assays, namely, the real-star Orthopoxvirus PCR and the TNF (tumour necrosis factor) receptor gene-based PCR for MPXV screening and confirmation, respectively.

In addition, the MPXV quantification cycle (Cq) was also assessed in the MPXV-positive samples. The conjunctival and eyelid samples were reported as MPXV-positive by both PCR assays. Post inoculation of the conjunctival sample (swab) in Vero E6 cells, cytopathic effects (CPE) were observed within two days, and viral replication was observed after two days, three days, and four days.  MPXV isolated from conjunctival swabs was found to be replication-competent in the absence of bacterial growth.

The patient was administered I.V. cidofovir (five mg/kg twice per week) with measures to improve fluid intake and oral probenecid) and eye drops comprising Vitamin A and anti-inflammatory agents with gradual tapering and subsequent stoppage of steroid supplementations. Cidofovir was administered to prevent the risk of vision impairments in light of the worsening clinical scenario.

The clinical condition gradually improved post-treatment with asynchronous lesion evolution followed by complete disappearance within two months of MPX onset. The slow pace of intraocular MPXV clearance and full recovery indicated the partial contribution of cidofovir antiviral activity to the resolution of clinical signs and symptoms.

Conclusions

The study findings underscore the development of potential ocular lesions in MPX cases identified in non-endemic settings. The authors of the present study believe that the case report is one of the first of its kind to describe ocular lesions in MPX due to replication-competent and infective MPXV, as observed in the viral isolation experiments.

Contrary to previous study findings, systemic symptomatology and ocular lesions were reported after the development of dermatological lesions in the present report, indicative of MPXV self-localization in ocular tissues based on MPXV spread from local inoculums. The findings underpin the enforcement of strict hygiene measures to decrease MPXV transmission. Further, the findings of slow MPXV clearance and clinical recovery after I.V. cidofovir administration may have implications for MPXV transmission and the pathophysiology of ocular involvement in MPX.